Insulation for armatures



J. F. CULLIN.

INSULATION FOR ARMATURES.

APPLICATION FILED 05u29, IsIs.

Im, 35? I F I I I WI I v I Il I I/ ,I I ..E I E E x Im I IIE E:: IIIIIHVIY@ 0I UNITED STATES PATENT oFFIca.

JASPER F. CULLIN, 0F DETROIT, MICHIGAN, ASSIGNOR, BY MESNE ASSIGNMENTS,

TO WILLIAM J'. HARTWIG, 0F DETROIT,

MICHIGAN.

INSULATION FOR ARMATURES.

Application led December 29, 1919. Serial No. 348,087.

To aZZ 'whom it may concern:

Be it known that I, JASPER F. CULLIN, a citizen of the United States, and residing at Detroit, in the county of Wayne and State of Michigan, have invented a new and Improved Insulation for Armatures, of which the following is a specification.

This invention relates to the insulation of the windings of the armatures of electric machines, and consists in simple and eiiective means to prevent electric currents from passing from one winding to another or from the windings to the core of the armature.

This invention consists in the details of construction illustrated in the accompanying drawings and particularly pointed out in the claims.

In the drawings, Figure 1 is a plan of a motor armature partly wound. Fig. 2 is a View of the front or commutator end thereof. Figs. 3, 4: and 5 are sections on the lines 3 3, 1-4, and 5-5 of Fig. 1. Fig. 6 is a view of the rear end of the armature. Figs. 7 and 8 are developments illustrating the construction of the armature. Fig. 9 is a perspective of a flat copper rod constituting a winding of this armature. Fig. 10 is a view of a piece of insulation.

Similar reference characters refer to like parts throughout the several views.

The shaft 1, the laminations 2 of the core of the armature and the segments 3 `and spool 4 of the commutator as well as the spacing collar 5 between the core and the commutator are of well known construction. Bars or rods which constitute the windings of the armature are usually increased in woven cotton sleevings which are properly 'treated to render them good insulations, but

in the present construction no such fabrics are employed. l

The laminations are formed with an unequal number of notches 6 in the usual manner, the present drawings showing 21 and also the same number of segments ofthe commutator, each segment having a radial projection 7 provided with a notch l8 to receive the ends of the bars A which constitute the windings. These' bars are of copper and comprise the eyes 9, and two sections, each consisting of an inclined portion 10, a longitudinal part 11, an inclined portion 12'and an end 13. The insulation of Specification of Letters Patent.

Patented Oct. 4, 1921.

these windings can best be pointed out by describing the manner of positioning these bars A.

Tough and strong strips 1'5 of paper-like insulation, bent U-shaped, are first placed 1n 'the grooves in the armature core, after which the straight portion 11 of one section of each winding is driven down to the bottom of its groove. During this process, the other section of each winding is swung out to permit a narrow tool to be inserted in the grooves in the core to drive the first sections to the bottom of the grooves. At the same time, the ends 18ct these first sections are also driven down to the bottoms of the notches 8 in the commutator segments.

During the positioning of these first sections, a ribbon 16 of indurated liber, rubberized duck or other. good insulating material is woven in over and under the inclined portions 10 of the rst sections, as indicated in Figs. 5, 6 and 7 so as to insulate these portions 10 of adjacent windings from each other. After this a similar ribbon 18 is wound around all the portions 12 at the commutator end of the armature.

A narrow strip 19 of good insulating material is now laid in each groove in the core and the second section of each bar A is bent down and driven into its proper groove onto this insulation. These grooves in the core must be made of such width that the parts 11 of the bars A must be driven in with considerable force but without destroying the insulating strips 15 which line these grooves. The ends 13 of the second sections of these bars are driven into proper notches inthe commutator segments where they are soldered in place later on. The described insulation has been found lsuiicient and satisfactory for the starting motors for automobile engines, which motors are operated by comparatively low current. The most desirable insulation 19 between the parts 11 of the bars A is produced 'by twlsting a narrow strip of insulating paper into a cord or tube, as indicated in Fig. 10, which seems to accommodate itself to the slight undulations electricians without departing from the spirit of my invention as set forth in the following claims.

I claim:

1. A cylindrical armature core provided with evenly spaced longitudinal grooves, armature windings comprising metal bars bent on themselves substantially midway their length to constitute two sections, a pair of sections of two windings being positioned in each groove, one inside of the other, means to insulate the windings in each groove from each other and from the core, andA a strip of insulating material woven in and out between the inner sections of the windings adjacent one end of the armature and extending generally circumferentially of the armature.

2. A cylindrical armature core provided with evenly spaced longitudinal grooves, armature windings comprising metal bars bent on themselves substantially midway their length to constitute two sections, a pair of sections of two windings being positioned in each groove, one inside of the other, means to insulate the windings in each groove from each other and from the core, and a strip of insulating material woven in and out between the inner sections of the windings adjacent one end of the armature and extending generally circumferentially of the armature andA flat strips of insulation extending around the inner sections and Within the outer sections of the windings at both ends of the armature.

JASPER F. CULLIN. 

